Electric jet-wave commutator and interrupter



Dec. 29,1925- 7, 7

. I J. F. G. P. HARTMANN ELECTRIC JET WAVE COMMUTATOR AND INTERRUPTER ,Filed May 19 1925 @UUU V5 hue 7 top;

awwmzzm 'ment of the invention,

Patented Dec. 29, 1325. i

UNITED -sTA'TEs PATENT OFFICE.

JjUnIns VFREDEERIK onone roux. HARTMACNN, or COPENHAGEN, DENMARK.

ELECTRIC JET-WAVE COMMU'IATOR AND INTERRUPTER.

Application filed May 19, 1925. Serial No. 31,351.

To all whom it may concern:

Be it known "that I, JULIUS Fnnonnm GEORG Pour, HARTMANN, a subject of the King of Denmark,-residing at Copenhagen,

Denmark, have invented new and useful Im-- provementsjin or Relating to Electric Jet- W ave Commutators and Interrupters; and I do hereby declare the following to be a full, clear, and exact description of the same.

The present invention relates to apparatus in which a wave-shaped conductive liquid,

jet is used for effecting the closing or interruptlon of an electric circuit, and partiou larly t9 the so-called jet-wave commutators of one or more sharp-edged members made of conductive material, preferably of high melting point, and of such shape and posi- 1 screened from the corrosive action of the. commutation or interruption sparks and W111 tion that the interruption takes place between the jet and a part of the member d1stant from the edge which latter 1s thus maintain its sharpness and be able to precisely cut the jet for long periods of time. It has been found that the material of which this sharp member is made should preferably have a melting point above 2000 C. and that Wolfram (tungsten) is well suited for this purpose. r

Referring nowto the accompanying draw- Figure 1 is a diagrammatic new of 81612- wave commutator,

' Figure-2 is a front view of an embodi- Figures 3 and4 are' ;a."front-viewand a v.plan view respectively of, a second 'em bodia a t a Figures 5.; and -6 are a front-vlew and a planview-rspectively of a' third embodiment, 4

' Figure 7 is a diagram, and

Figure 8 is a front view of a jet wave com- 7 mutator including a fourth embodiment of the invention.

Figure 1 shows a commutator bf known type which contains a waveshaped liquid,

jet, or shortlya jet-waved, preferably of mercury, whlch issues from a nozzle N and moves on in the direction of the axis of the wave-figure and strlkes an electrode (main electrode), generally but notalways, a two part electrode E E the component parts E and E of which ordinarily are separated byvan insulating wall P having a sharpened edge which cuts the bends of the jet-wave. The et-wave being during its movement towards the double electrode E E in constant touch with an auxiliary electrode E, will alternately connect this latter electrode with the electrode parts E and E The jet J,

the double-electrode E E and the auxiliary-electrode E thus form together a commutator whlch'may be used for the rectification of an alternating-voltage. For this purpose the waves are generally produced by the co-actio'n between a constant magnetic v field F and an auxiliary alternating current which is synchronous with the voltage to be rectified. This current may be delivered from the secondary T of a transformer and sent into and out fromthe jet through the nozzle N and an auxiliary electrode E. Furthermore in order to make the commutator serviceable for the rectification of the altermust be, adjusted atsuch a distance from the field, that the jet-bend is out nearly at the moment in which the alternating voltage alters its sign.- I

The improvements more particularly described in the following mainly relate to the main electrode of such a jet-wave commutator, but may also be used in any other apparatus in whicha jet-wave conductor is used for the closing or interruption of an electric circuit. It has been found that the wall P, Figure 1,-can be entirely omitted, if the innermost edges of the two electrodepieoes E and E,, that is the edges or and b, are formed as protruding knife-edges for instance as shown in Figure 2. .With this arrangement the commutation takes place in the following manner. The jet-wave, travelling down towards the electrode, is first cut and very precisely out, by one of the edges, in Figure 2 the edge 0;, but if the innermost surface of the electrode-part E is nearly vertical the connection between the jet J and the electrode-part E is not niiitation spark is ina way made harmless as the spark is formed between the end of the jet bend c, Figure 2, and the lower edge (l of the electrode-part E (or E The spark thus does not attack the edge a (or b) from which it follows that the exactness of commutation is not diminished through the wearing out of the electrode. If the innermost parts A and B of the electrode-sides E and E are made of a material of high" melting point especially Wolfram (tungsten) the wearing out of the electrode is, with proper dimensions of the same, a very slow process.

A special form of an electrode made in accordance with the principle now explained is shown in Figures 3 and 4:. Thetwo electrode-sides E and E here consist each of a series of knives or wedges of which, however, only the two innermost knives V and V are of consequence as regards the commutation-process, and only these two knives need be made of special material. The two innermost knives or wedges may be insulated so that resistances or other electrical devices can be connected between them and the remainder of the electrode sides E and E respectively. In the two embodiments of the invention described above the cutting of the jet bend does not take place inthe middle-plan of the commutator. In certain cases this may be a disadvantage, which can be overcome by constructing the electrode as shown in Figures 5 and 6, where between the two electrode sides E and E a. knife or wedge V of a conductive material is inserted.

I This knife is insulated from both electrode parts 7E, and E The commutation now takes place in the following way. Just before the interruption of the connection between the jet J andlthat electrode side, in Figure 5 E which the jet is leaving, the connection is upheld by the conductive middle-knife and the stringS drawn out between that knife and the j et-bend. Shortly after the bend has reached the edgev b of the other electrode side, the string breaks down and a commuta-' tion spark appears. As above the spark does not attack the edge of the knife, which has cut the bend, but only the back of the knife, that is a part which is capable of standing,v the influence of the spark much betteri than the edge'and apart, the condition of which to a very high degree is unessential to the working of the commutator.

The electrode sides E and E of the device shown in Figure 5, may be given any shape,

knife V ought to be made of a material with a high melting-point, preferably tungsten. Often it will, however, be found advisable also to use such a material for the two front knives V, and V because these knives are located near to the spark. As above one or more of the knives of the two electrodesides may be insulated in order to make possible the insertion of electrical contrivances between the knife and the remainder of the electrode or between the knives themselves. In a similar way electrical devices, say resistances, may be inserted between the middle point of the electrode (the knife V and the middle-point of the transformer-windings ,on which in case of a recti'fier, the double electrode is working. In Figure 7 there is shown such an arrangement with a resistance R connected between the knife V and the middle-point of the transformer-winding T T The insulatedmiddle-knife may be divided into several separate knives arranged in various ways. Figure 8 shows a jet-wave commutator having a triple-knife V V the side knives to such a level that the two strings S and S breakdown simultaneously. Hereby two commutation sparks are formed Y instead of one, the wear due to the sparking thus being distributed on two knives and in accordance herewith the load and voltage,

which can be commutated by means of the electrode being increased. This complex knife-arrangement may be varied in many ways. For instance the middle-knife V in Figure 8 may be removed. The remaining knives V and V in this case could be left in the position shown in'Figure 8 or they might be lowered to the level of the electrode-sides, their mutual distance being simultaneously increased. Ifthen they were connected with the electrode sides E, and E respectively eitherv directly or through resistan'ces the construction would be similar to those shown in Figures 2 and 3.

Having thus fully described my invention I claim as new and desire to secure by Letters Patent:

1. In an electric jet-wave apparatus the The middle-knife V is raised above 1.05

combination of means for producing a 0on of conductive material adapted to cut the bends of said jet-wave, said-conductive memher being so shaped and positionedthat'the interruption of an electric currentv passed through said jet-wave takes place between the jet-wave and apart of the said conductive member distant from its sharp,

which is thus screened from the corroslve action of the interruption-sparks.

2. The device ,of claim 1, in which the sharpedged member is made of a conductive material having 2000 C. V

a melting point above 3. An electric jet-wave commutator, comprising means for producing a conductive et-wave. an electrode which is in constant 'touchwith the jet-wave, a double" electrode;

8 screened from the corrosive' action of (the the two parts of which are ada ted 'to be alternately connected with said rst-named electrode through said jet-wave, and at least one sharp-edged member of conductive material adapted to cut the bends of said jetwavewhe'n they ap roach saiddouble-eleq trode, said member ing so sha d and positioned that the interruption o anelectric current passed through said jet-wave takes place between'the jet-wave and a part of the said conductive member distant from the sharpk'edge of the same which is thus sparks.

- 4, The device of claim-e, in which the hen s of the jet-wave is insulated from and adj ted in the middle plane of the doubleelec rode coacting with the jet-wave. I

5.'The device of claim 3, in which'three insulated knives ,of conductive material adapted to cut the bends of the jet-wave are arranged symmetricall in relation to the middle lane of the ouble-electrode with which t e jet-wave co-acts and with such relative knives.

"shar -edged conductivemember cutting the sitions that the cutting of the jetwave ta as place simultaneously. at two 6. The device of claim 3, in which 'two' knives of conductive material adapted to cut the jet-wave are arranged symmetrically in relation to the middle-plane of the doubleelectrode with which the jet-wave coacts;

7. The device of claim 3, in which ,two knives of conductive material adapted to cut the jet-wave are arranged symmetrically in relation to the middle-plane of the double-' electrode with which the jet-wave co-acts and art of one or other of the. 

